Electrical switch with improved actuator means



Oct. 29, 1968 DAVlEs 3,408,462

ELECTRICAL SWITCH WITH IMPROVED ACTUATOR MEANS Filed Dec. '19, 1966United States Patent 3,408,462 ELECTRICAL SWITCH WITH IMPROVED ACTUATORMEANS Gwyn Davies, Cwmbach, Aberdare, Wales, assignor to A.B. MetalProducts Limited, Abercynon, Glamorgan, Wales, a British company FiledDec. 19, 1966, Ser. No. 602,918 Claims priority, application GreatBritain, Sept. 9, 1966, 40,467/ 66 6 Claims. (Cl. 200-6) ABSTRACT OF THEDISCLOSURE An electrical switch of simple construction wherein movingcontacts are pivotally mounted intermediate the end for rocking movementon supporting members which are yieldable. A rotary cam is locatedbetween the yieldable supporting members and has a pair of lobes whichbear continually on the moving contacts and press them towards or awayfrom the fixed contacts depending on the relative position of the lobesand pivot points. During movement of the lobes the yieldable supportingmembers tend to part and reclose to maintain mechanical engagementbetween the lobes and the movable contacts.

This invention relates to electrical switches and more particularly to asimple and compact switch construction adapted generally for switchinglow power circuits in such systems as radio, television and otherelectronic apparatus.

A previous proposal has been made for an electrical switch comprisingmovable contact members pivotally mounted intermediate their ends forrocking movement on spring urged supporting members, and actuating meansmovable between the supporting members to part them against the springaction and to rock the moving contact members about the supportingmembers.

This arrangement has only been used hitherto with a longitudinallymovable actuating means, and it is an object of the invention to providesuch an arrangement with a rotary actuating means.

The invention consists in an electrical switch comprising movablecontact members pivotally mounted intermediate their ends for rockingmovement on spring urged supporting members, and rotary actuating meanslocated between the supporting members and having portions bearing onthe movable contact members, rotation of the actuating means causing thesaid portions to cross over the supporting members, which part againstthe spring action and re-close, and rock the movable contact members.

The invention will be further described, by way of example only, withreference to the accompanying drawings wherein:

FIGURE 1 is a plan view of one embodiment of switch according to theinvention, with a cover removed for clarity of illustration;

FIGURE 2 is a vertical cross-section on the line 11-11 of FIGURE 1; and

FIGURE 3 is a perspective view of a detail.

Referring first to FIGURES l and 2, a switch embodying the presentinvention is mounted on a supporting member 1. The supporting member isgenerally manufactured from metal but can be of a moulded construction.

This supporting member has apertures for accommodating an operatingdevice 2a of generally conventional construction mounted on a rotor 2 ofa potentiometer or the like and co-operating with lugs 11 projectingfrom a tumbler 3 carried by a body 4 or base of the switch.

The body 4 or base of the switch is of general circular ice section andhouses all the metal contacts. The body 4 or base is preferably ofmoulded construction using phenolic or alkyd plastics.

The body 4 or base of the switch is suitably formed with apertures andbarriers to house the contacts 5, 6, 7,8, 9 and 10 and a suitable pivot3a to locate the tumbler 3 centrally between the moving contacts 7 and 8and the supporting contacts 5 and 6. The said pivot is of suitablelength to locate the switch body 4 onto the support memher.

The various contacts are made of a suitable metal such as copper, brassor phosphor bronze and may be silver plated. The contacts are six innumber and are deployed three each side of the body 4. The springcontacts and supports 5 and 6 are made from phosphor bronze or similarspring material and are fixed to the body 4 by means of staking ordeforming the metal so as to fix them rigidly into the body 4. The freeends of these spring contacts are short marginal extensions forming afork capable of locking and pivoting moving contact arms 7 and 8 whichare notched part Way along their length and located in the forked endsof the spring contacts 5 and 6 providing a keying of the two parts and agood electrical connection.

The fixed contacts 9 and 10 located at the opposite end of the body 4provide two electrical connections required on this switch unit and arestaked or deformed so as to rigidly fix them into the body 4.

The tumbler 3 (see FIGURE 3) is made from high quality insulationmoulding material such as phenolicglass-filled nylon or alkyd and ispivotally mounted on the pivot 3a and is held in position by thesupporting member 1.

The tumbler 3 mounted upon the pivot pin is of suit able proportions tocover the width of the moving contacts 7 and 8 and moves through aprescribed arc limit by abutments 13 cooperating with a projection 14 onthe body 4. The tumbler 3, upon being turned by the operating device 2aupon the pivot, maintains mechanical contact with the two movingcontacts 7 and 8 the whole time.

Because of the pivot effect brought about by the forked form on thespring contacts 5 and 6 and the notching of the moving contact arms 7and 8 the spring contacts 5 and 6 deflect as lobes 12 on the tumbler 3pass over the fulcrum points. At the same time, the lobes 12 create arocking action upon the moving contact arms 7 and 8, causing thecontacts to complete the two circuits. Reversal of the aforesaidoperation opens the two circuits and switches the unit off.

The switch embodying the present invention is well suit- I ed forswitching such circuits as those embodying silicone diode rectifiersused in modern television receivers and provides a rugged constructionhaving great operational adaptability.

Various modifications may be made within the scope of the invention.

I claim:

1. In an electrical switch comprising a body, a pair of fixed contacts,a pair of spring urged supporting members mounted in the body and eachhaving one free end, the said free ends being spaced apart, a pair ofmovable contacts having intermediate portions mounted one on each of thefree ends for rocking movement of the movable contacts about the saidintermediate portions into and out of engagement with the fixedcontacts; the improvement comprising rotary actuating means mounted inthe body and located between the free ends of the supporting members andhaving a pair of actuating portions bearing directly on the movablecontacts adjacent the said intermediate portions whereby rotation of theactuating means causes the actuating portions to pass over the free endsof'the supporting members, which yield against the spring action andreturn to maintain continuous mechanical engagement between theactuating portions and the movable cont-acts, the movable contactmembers being thus rocked about their said intermediate portions foractuation of the switch.

2. An electrical switch as claimed in claim 1, wherein the rotaryactuating means is rotatable about an axis coplanar with the free endsthe actuating portions are diametrically opposed lobes-causingsimultaneous rocking of the movable contacts;

3. An electrical switch as claimed in claim 1, in which the rotaryactuating means has abutments thereon, and in which the body hasabutments thereon cooperating with the abutments in the actuating meansto limit rotation of the actuating means to a minor arc.

4. An electrical switch as claimed in claim 1, comprising drive lugsprojecting from the rotary actuating means.

1 5. An electrical switch as claimed in claim 1, in which the supportingmembers inherently resilient and are elec- -trically connected to themoving contact-members.

6. An electrical switch as claimed in claim 1, in which the supportingmembers have short extensions and the movable contact members arenotched for cooperation with andlocation on the said short extensions.

References Cited UNITED STATES PATENTS 2,202,698 5/1940- Latta 200-62,776,356 l/195'Z Kling 338198 X 2,970,199 1/1961 Dull et a1 2006 X3,050,604 8/1962 ,Kusche 200-6 X 3,251,956 5/1966 Rasor et a1. 200-6 X3,310,642 3/1967 Zeller 2006 X LEWIS H. MYERS, Primary Examiner.

J. R. SCOTT, Assistant Examiner.

